Thanks to LOTS and LOTS of debugging help from Toni Wilen we now have got a fully working custom ADF of The Champ!
Done with SuperDuper. (standard ADF => custom ADF)This is needed for the game. This one even works on WinUAE 0.8.17 R2 (just tested)!

You're welcome.
Note that the first one uploaded in the zone is from Toni, not from me.
Mine is a bit different. Dunno where Toni created his one from. At least mine has been created from warlock99's fully-working image after testing it on my REAL A500!
Only Andy's version worked for me on the real thing.

This game is still not in TOSEC after this long period of time.
I re-uploaded the STANDARD image (this one will only work on the real thing) and the custom ADF. [Thanks Cody for re-sending the latter one]